By means of lifting devices attached to cranes, many goods are lifted and moved for example in ports, warehouses and many other places. Various kinds of pallets on which products, goods, equipment and so on are placed are usually moved with the so called pallet trucks. Typically, there are lifting arms, that is a so-called fork, in pallet trucks, which is comprised of two or several mainly horizontal arms. In pallets, there is a bottom on which goods are placed and under the bottom, there are supports projecting downwards. The pallet lies on the ground on its supports such that between the surface of the ground and the bottom of the pallet there remains a space where lifting arms of a pallet truck may be pushed. The space is somewhat higher than lifting arms such that lifting arms fit into this space. By means of pallet and other trucks also other kind of loads besides pallets may, naturally, be lifted. It is essential that under a load there is a space into which lifting arms of a lifting device may be pushed. For example, wood is moved in great quantities by means of various lifting devices from one place to another while loading, for instance, wood. There are also other kinds of lifting devices functioning by means of their own power source, which devices are moved and employed without cranes or similar.
While employing present lifting devices a person is usually always needed on the lifting/moving place or on the ground to place the lifting arms on place. While a lifting device is moved with a crane and it rests on transporting equipment and lifting devices of the crane, it is possible to lower it down on the right place relatively exactly such that the lifting arms are at the point of the pallet or similar, but while moving the lifting arms to the space under the pallet or a load there may be difficulties because the space is relatively small and the lifting arms must be in the air off the base while moving the lifting device. After moving the pallet or some other load is placed to the desired place and the lifting arms are pulled from under the pallet or similar. Usually, at this point, also a person present there is needed to guide/help to take the lifting arms from under the pallet or similar. The problem is that with a crane, lifting arms may not be moved and placed exactly, reliably and fast under the pallet or similar to the right place and/or removed after transporting without the help of a person present there. This person has to put lifting arms in place and to remove them. These people must often work in relatively narrow places and lifting devices are of great size and heavy, especially while moving pallets or similar loads. In this kind of places, hazardous situations may occur and special attention must be paid on safety at work. While a separate lifting device with its own power source is employed, there must be a worker near the lifting device.